1). Field of the Invention
This invention relates to a semiconductor substrate processing apparatus and a method of processing a semiconductor substrate.
2). Discussion of Related Art
Integrated circuits are formed on semiconductor wafers. The formation of the integrated circuits may include numerous processing steps such as deposition of various layers, etching some of the layers, and multiple bakes.
Often the processing of semiconductor wafers takes place in large wafer processing machines. One of the components found in these machines are known as modules. These modules may receive a semiconductor wafer from a another component, place the wafer on a wafer support, and dispense a solution or solvent onto the wafer as one of the many steps included in wafer processing. The solution may be dispensed onto the wafers from a dispense head that is moved into a position over the wafer. Typically, the solution is fed into inlets of the dispense head through a valve and dispensed onto the wafer through nozzles on the dispense head.
After the solution is dispensed, unwanted solution often leaks or drips onto the wafer or another part of the module due to vibrations of the dispense head as it is moved, extra solution remaining in the dispense head, and air rising through the nozzles on the dispense head. This unwanted solution can damage the integrated circuits that are being formed and lead to increase maintenance costs of the wafer processing machine. One solution is to use a “suck-back” valve on the dispense head, which creates a vacuum back though the inlet causing excess solution to be drawn back through the inlet. However, the suck-back valves are expensive and are not completely effective as some solution still leaks from the dispense head.